I suppose this is a question for the future than the present. I've run a few games at Gencon before and thankfully they typically go on time or a bit over. I suppose it's a bit of me typically planning more than I need.
But are there repercussions for going under the allotted time due to unplanned circumstances? I suppose the players 'beat' the game in 3 hours out of your 4-hour adventure.
Asking for a future event, thanks!
If I'm understanding the rules correctly, if you deliver more or less what you said you were going to do ("we're running Module X for Game System Y, characters provided"), and the players are satisfied with what they received, then it's no problem. Going a little over, a little under, or a bit off the rails is something that happens, "nature of the beast" kind of stuff. A group of players "beating" a scenario early through skilled play is likely going to be more satisfying than leaving a game unfinished due to time shortage or getting TPK'd.
If the players are unsatisfied with what they received, the most likely "consequence" is that they won't play with you again. Con play is very much a "pay your money and take your chances" sort of thing, and most folks will just take the "L" if a game turns out to not be what they want. If they're wanting something else, like a refund, they'd need to plea their case to the Staff, which is going to be a tough roe to hoe because A) the refund policy is for games failing to go off entirely (DM no show or lost vital equipment, no-show players result in insufficient party size) versus just not liking a game, and B) good luck explaining to a Hall Captain that the DM ran literally the whole game for you but you still want your cash back.
It's natural for games to go longer or shorter than anticipated, depending on how the play unravels. A good GM will attempt to move things along if it is going slowly, will ask for some feedback/debrief at the end if things are going quickly, etc.
Whenever I GM at a con, I always add an extra 30-60 minutes to game time, to allow for running over. This means that I usually finish a bit early, and none of my players have ever complained about it. We typically take a few moments to relive the best moments of the session.
FWIW, in 2021 I played the D&D adventures in the catacombs at Gen Con. I'm typically a 'think out of the box' person when I RPG, so when we came across an undead army clearly meant to attack us, I used my persuasion skills to convince their leader that we were on his side, serving their undead king and wanting to destroy that other big baddie in the dungeon (the second part was even true). We actually got both groups of enemies to fight each other, rather than having 2 massive battles ourselves. Everyone loved it, but because we spent a lot less time in combat than anticipated, we finished about an hour early. No one complained, even though it was an expensive event. We left early, happy and smiling. The moral is, if the players have a good time, that's all that matters.
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